refactor: more detailed error when FF-A version is incompatible

Print more detailed error messages when the version specified by a call
to FFA_VERSION or in a manifest is incompatible with the compiled
version.

Change-Id: Ia5818dc2dfb5813cb4637d13bd5b8de30f22d1b7
Signed-off-by: Karl Meakin <karl.meakin@arm.com>
diff --git a/src/manifest.c b/src/manifest.c
index 44436df..f9d1703 100644
--- a/src/manifest.c
+++ b/src/manifest.c
@@ -1091,9 +1091,13 @@
 	/* ensure that the SPM version is compatible */
 	ffa_version = vm->partition.ffa_version;
 	if (!ffa_versions_are_compatible(ffa_version, FFA_VERSION_COMPILED)) {
-		dlog_error("FF-A partition manifest version %s: %u.%u\n",
-			   error_string, ffa_version_get_major(ffa_version),
-			   ffa_version_get_minor(ffa_version));
+		dlog_error(
+			"FF-A partition manifest version v%u.%u is not "
+			"compatible with compiled version v%u.%u\n",
+			ffa_version_get_major(ffa_version),
+			ffa_version_get_minor(ffa_version),
+			ffa_version_get_major(FFA_VERSION_COMPILED),
+			ffa_version_get_minor(FFA_VERSION_COMPILED));
 		ret_code = MANIFEST_ERROR_NOT_COMPATIBLE;
 	}